After many years of experience in postpaid charging of telecommunications calls, telecommunications service providers and their customers are becoming increasingly interested in real time charging which offers cost control and immediate balance update.
In response to these demands, the new generation of telecommunications systems such as those specified by 3GPP (3rd Generation Partnership Project) and 3GPP2 (3rd Generation Partnership Project 2) have introduced new and highly flexible billing arrangements. These billing arrangements are described in a standards document as Diameter billing arrangements.
In accordance with these Diameter billing arrangements, call authorization and billing services are provided by a group of Diameter servers, which store a customer profile and maintain billing records and account data for their served customers. These servers are accessed (optionally via a Diameter agent), and respond to billing inquiries from calls originated in a network by providing information to the Diameter client process controlling the billing aspects of a call. Because of a need to have a high degree of flexibility in the assignment of identifications of customers and because of the very large volume of billing inquiries and responses, it is necessary to provide a large number of Diameter servers in a network and to provide essentially complete flexibility in the assignment of subscribers to individual Diameter servers.
In accordance with one Diameter billing arrangement, the Diameter client comprises a database for storing the identity of the Diameter Server for serving each subscriber of the network. This arrangement creates problems for keeping all Diameter client databases up to date and in synchronism, and requires a large database in each Diameter client. For both of these reasons, if the number of subscribers served by a Diameter system is large, this arrangement is undesirable.
Accordingly, a problem of the prior art is that there is no efficient system for determining the identity of the Diameter server of a particular customer without incurring a penalty in call setup time of a telecommunications call.